I was hanging out on the counter the other day when a client came in asking about Pigeon Fever. My ears perked up at the thought of chasing pigeons, but it turns out this conversation had nothing to do with birds. Pigeon Fever is a syndrome caused by a very specific bacterium, Corynebacterium pseudotuberculosis, which leads to abscesses. This bacteria hasn’t been a big problem for Floridians since it prefers dry weather but lately it’s decided hot and humid isn’t so bad!

What is Pigeon Fever?

Let’s start with a little bit of learnin’. Pigeon Fever, or Dryland Distemper, is a relatively common problem in the hot, dry regions of our desert southwest. For reasons the experts don’t really understand, the organism has been marching its way across the country to wetter regions. C. pseudotuberculosis is perfectly content to live in soil until drought conditions occur. At that time it seems to begin looking beyond the ground for somewhere to live and reproduce. The bacteria is readily spread by common insects like the stable fly, and infects horses through any small wound.

Diagnosing

The most common appearance of Pigeon Fever is a large swelling of the chest, so the horse looks like a pigeon. While the chest is the most common location, Pigeon Fever can cause swellings anywhere. Upon further examination, the swellings turn out to be large abscesses.  Another, less frequent problem, is what’s known as ulcerative lymphangitis. This is a big, swollen, oozing infection of the leg. Even rarer is an invasion of the internal organs such as the kidney and liver by the organism.

Treatment

Once my Docs have decided that a C. pseudotuberculosis abscess is likely to be the problem, they will start treatment by draining the abscess and flushing the area. The tricky part is any pus that hits the ground can contaminate the entire area, so all pus must be contained and disposed of properly. My Docs try to open them on concrete so bleach can be applied to the area. 

Opened and regularly-flushed abscesses generally heal rapidly with minimal scarring. However, Ulcerative Lymphangitis can be very difficult to treat. These horses are placed on aggressive antibiotic therapy with both injectable antibiotics and highly concentrated therapy into veins in the affected leg. The leg is kept bandaged to help reduce swelling, absorb drainage, and keep antimicrobial ointments in place. Unfortunately, chronic scarring of the leg and repeated infections are often leftover effects of this form of the disease. Infection of the internal organs is treated with rest and aggressive antibiotics with a full recovery the usual outcome.

Prevention

Prevention is aimed at controlling insects in the stable area and making sure any wounds are regularly addressed. The very bottom of the abdomen is a common area for us to see insect bites leading to open skin and excellent entrance sites for many diseases. Equishield IBH salve is the best way my Docs have found to prevent this problem. Several groups are working on a vaccine, but so far they have had no luck.  

I know we were all hoping Pigeon Fever would stay out West, but it seems to be here to stay in Florida. If you notice a swelling, and it’s not going down after a day or two, call my Docs. They’ll get you all fixed up!

Until Next week, 

~Tony

P.S. Note to the social calendar: I expect to see all my loyal readers this coming Saturday, November 20th, from 10am-1pm at Springhill Equine for our Annual Open House. It’s sure to be a good time, and it’s a great opportunity to meet me in all my feline glory.

As a horse person, you are probably familiar with your horse’s guttural pouches, although you may not be familiar with what they are and the issues they can cause for your horse. For those of you who don’t know, let’s first discuss exactly what it is. Bear with me; as the most superior species, cats do not have guttural pouches, so I had to do a bit of research to determine what this structure is all about.

As I’ve always suspected, horses are indeed just full of hot air, as can be explained via their guttural pouches, which are, in fact, sacs of air. They’re on either side of the head just below their ears, and are an expansion of the eustachian tube which is the structure that prevents air and fluid from building up within the ear. A horse’s guttural pouch can hold up to an entire mug of coffee per pouch!

Within the pouches are some very vital structures including veins, arteries and nerves, covered by just a thin membrane. As you can imagine, when there is a problem with the guttural pouches those vital structures are at an increased risk for damage. Damage to these structures can lead to difficulty swallowing, breathing, facial expression and head posture problems. The most familiar problem is Strangles. However, there are other issues that can affect the guttural pouches, including guttural pouch mycosis, guttural pouch tympany, and temporohyoid osteoarthropathy. I know, it’s a mouthful, even for me.

Guttural Pouch Empyema

When I hear the word empyema, my mind immediately goes to food, and I think of empanadas. While empyema seems like a pretty fun word to say, and we all know I really love thinking about food, what it stands for is not fun or delicious. Empyema is the fancy doctor-word for a pocket of pus. Most commonly, empyema of the guttural pouches is caused by a bacterial infection. One such bacterial infection that can affect the guttural pouches is streptococcus equi equi, otherwise known as Strangles. The pus caused by the bacteria forms in guttural pouch and can drain through the eustachian tube into nasal passages and nostrils. Accompanying thick, mucoid nasal discharge are clinical signs including fever, depression and swelling under the jaw.

However, unlike other guttural pouch diseases, guttural pouch empyema does not usually affect the vital structures. As the name Strangles implies, the swelling under the horse’s jaw can become so enlarged and painful that the horse can have difficulty breathing to the point of respiratory distress. Rarely, the pus that forms in the guttural pouches fails to drain and can precipitate into hard balls called chondroids. As with all other balls associated with animals, these balls must be removed surgically. If they go undetected, horses can be silent shedders of the bacteria and spread Strangles without their owners knowing it.

Treatment for Strangles is supportive and includes anti-inflammatories, antibiotics and, rarely, surgical drainage of the guttural pouches. Strangles is one of the biggest reasons to never share water buckets, troughs, feed buckets, etc with horses you do not know.

Guttural Pouch Mycosis

Man, fungus really does like to cause problems for horses, from eyes to wounds to their guttural pouches. No matter the form, fungus is one of the most difficult and potentially deadly organisms that horses are up against. When a horse’s guttural pouch(es) becomes infected with a fungal organism, it attaches itself to the top of the guttural pouch, going undetected. Once attached there, it eats its way through the thin lining and attacks the nerves and arteries. Since the fungi go undetected and do not fill the guttural pouch like empyema does, clinical symptoms occur very rapidly and can be dramatic.

One of the most common symptoms of guttural pouch mycosis is bleeding from the nostrils. It can range from a trickle to profuse bleeding, which can quickly result in the horse’s death. If the fungal organism affects the nerves in the guttural pouches, mild to severe symptoms may occur. Mild symptoms typically resolve, however, severe symptoms can lead to respiratory distress, trouble swallowing, and other life-threatening problems that are nearly impossible to recover from. And I thought diabetes was a pain to deal with!

Guttural Pouch Tympany 

As if horses were not already poorly designed, they can also develop a congenital problem associated with their guttural pouches called guttural pouch tympany. This affects foals very shortly after birth. Their guttural pouches fill with air that’s unable to escape. Oftentimes they can look like adorable little chipmunks (well, BIG little chipmunks). Usually, guttural pouch tympany does not cause major issues, but it can occasionally lead to difficulty swallowing and breathing. The only way to correct this problem is with surgical intervention. Of course, it can never be an easy fix with horses. They always have to make things as difficult as they can.

Temporohyoid Osteoarthropathy 

Ear infections are the actual worst thing ever. I know, because I have them all the time. One thing horses do right: they do not usually get ear infections. Yes, I said usually. As we all know, there are always those 1 or 2 horses out there that like to break the rules. On the rare occasion that a horse develops an ear infection, it may end up affecting the middle ear. As we have already discussed, the ear and the guttural pouches are interlinked therefore, a middle ear infection can affect structure close to the guttural pouches.

The stylohyoid bone forms a joint called the temporohyoid joint, which can be visualized along the roof of the guttural pouch. If the middle ear infection progresses, it can lead to infection of the temporohyoid joint and stylohyoid bone. Once infected, the joint and bone become thickened and brittle and can eventually fracture with movement. As the fractures heal, boney changes occur, callus of the bones form, and arthritis can develop. Callus formation and enlargement of the joint and bone can impinge on the nerves within the area. The most commonly affected nerve is the facial nerve, which affects facial expression.

If the facial nerve becomes damaged, it can lead to a droopy ear, droopy eyelid, and/or droopy muzzle on the affected side. More severe damage can even result in a head tilt and incoordination. Antibiotics are the go-to choice of treatment for a mild infection. More severe infections result in removal of a portion of the stylohyoid bone which allows the tongue to continue to function normally but alleviates the pressure on the facial nerve. Without intervention, it is possible that damage to the facial nerve may not fully resolve, and the symptoms associated with facial nerve paralysis may persist even after treatment.

As can be seen, problems with guttural pouches are far more than Strangles, and require quick recognition by the owner and swift treatment by your veterinarian. There are other diseases and problems that can be associated with the guttural pouches beyond what I have discussed, however, they are rare. If you think your horse may be having an issue that is associated with their guttural pouch(es) please contact your veterinarian as soon as possible.

Until next week, stay warm and pet the cat!

~Tony

P.S. There is a Meet Tony event coming up! Well, the humans are calling it Open House here at the Clinic on November 20^th, but it’s mostly about me. Mark your calendar, and come hang out with me from 10am to 1pm. There will be raffles prizes, drawings, and I’m even giving away a free Wellness Plan! I mean, what more could it take for you to come scratch my ears and give me a treat?

Hey, kits! This week I’m going to fulfill a reader request (yes, I can read) and frequent topic of quandary around here: fecal water syndrome. Before you accuse me of coming up with fancy names for diarrhea, let me assure you, fecal water syndrome is different. These horses have normal, formed manure, along with poop-colored water, and both are expelled at the same time. That lovely brown watery substance then sticks to the tail and hindlimbs to create as much work as possible for you, the human caretaker. So without further adieu, let’s talk watery poop!

What is it??

“Differential defecation of solid and liquid phases” is how it was described in a research paper from 2020. Seems an appropriate description! That’s exactly what these horses do; they poop normal solid apples, along with brown colored water. Very different from diarrhea. Some horses also show some signs of painful defecation as well. This is often demonstrated by picking up and replacing alternating hind limbs. You humans would probably call it ‘the peepee dance’ in a 4-year-old child. However, many horses show no signs of pain, in general, or discomfort of any sort. These horses are similar only in the fact that they both have excess fecal water.

Who gets it?

The study mentioned above found the syndrome in all colors, breeds, ages, and sexes of horses. Older geldings with bad teeth were slightly overrepresented. However, in most horse studies where age is a factor, older geldings are also overrepresented (small rabbit hole here!). It is generally thought that this occurs because geldings are more likely to be well loved older horses due to their good behavior (like me!).

I feel this should be a warning to all chestnut mares out there. It also likely reflects that mares and stallions may be used for breeding, and this is generally linked to increased health problems at younger ages. This study was looking at haylage consumption in particular, but in the process found that horses of all kinds of different sorts of feeding regimes were susceptible to fecal water syndrome. 

So what’s going on in there?

Great question! Most smart humans agree, they don’t know (which is why they asked The Cat). There’s almost certainly some disruption of the normal bacteria, viruses, and fungi in the GI tract. Yep, that’s right – the normal GI tract has all those icky-sounding things. But why this disruption happens is the $64,000 question. Current best thoughts among smart humans like my Docs are:

1. A GI tract that can’t handle long stem forage (probably a significant factor in the senior horse that’s got bad teeth)
2. A GI tract that doesn’t like grain
3. An inflammatory response in the GI tract (think allergies here)
4. A general revolt by the good bugs in the gut with a takeover by the bad guys

So you can see it’s a complex question with a lot of potential answers. One thing I did find interesting in my research for this week’s blog, is that horses with fecal water syndrome also have a higher reported incidence of colic than normal horses. 

Treatments!

Surely, I jest. If no one knows why this happens, how can even smart humans like my Docs treat them? Well, treatment is aimed at making the GI tract happy. But how??? Let’s start with basic guidelines. With any treatment, time is needed. This means patience, which is not something you humans do well. It’s not easy, but it usually starts with diet changes, and having patience.

My Docs start by evaluating the diet and then, depending on their findings, either increasing hay, or getting rid of it altogether. I realize this sounds drastic, but poopy water causing stinky, icky tails and hind legs calls for drastic measures! This diet change will be tried for at least 3 weeks. Along with diet changes, a good probiotic that contains Saccharomyces boulardii is added in. If no improvement occurs, then the next step is usually anti-inflammatories in the form of low doses of steroids like dexamethasone. These work by telling the gut immune system to calm down, stop being so dramatic, and let everything settle. A typical course of treatment would start with a higher dose, then taper down. 

Finally, if diet changes and anti-inflammatories don’t work, my Docs pull out an antibiotic called metronidazole. This antibiotic is used to kill a group of bacteria called anaerobes. The most common bad guys in the GI tract (human and horse) are anaerobes. Metronidazole has a slightly different use here than the wholesale destruction of bacteria antibiotics usually perform. Here, metronidazole is used to decrease the numbers of anaerobes and try to set up a better environment for the happy bugs. This means lower doses, or tapering doses may be used which is way, way different than the way antibiotics are normally prescribed. 

Sometimes one or more of these combined treatments helps, sometimes not. If these treatments fail, my Docs generally recommend allergy testing or limited source diets to see if an allergic cause can be narrowed down. They may also bring in an equine nutritionist to evaluate all kinds of things like fiber and starch content of the diet, and to help formulate a balanced diet if limited ingredients are going to be tried. My Docs may also try something called fecal transfaunation. This involves taking the manure of a normal healthy horse, mixing it with water, and giving it via NG tube to a horse with fecal water syndrome. Like all treatments for fecal water syndrome, sometimes it works, sometimes it doesn’t.

Besides the endless tail and leg washing, fecal water syndrome is a giant pain in the behind (literally!!!). With a lot of patience and some experimenting with feed sources, good probiotics, and maybe some pharmaceuticals, my Docs can work with you to get your horse back to normal. Now, be a good human and scroll down a bit and subscribe to my blog, if you haven’t already!

Until next week,

~Tony

P.S. If you want to take a really deep dive into fecal water syndrome, my docs did a podcast on this very topic! Just hop over to the Podcast Page and scroll down through the list until you see it. I’m sure you’ll see 

Horses are high maintenance creatures, have you noticed? Way worse than us cats. They require a careful eye to make sure they stay healthy and in good condition. One of the ways you horse owners can monitor your horse’s health is to keep track of his weight.

Knowing how much your horse weighs will help you keep an eye on weight gain and weight loss through the seasons, so you can adjust his feed accordingly. If he is overweight, you probably know that he is at risk of developing laminitis – a serious concern. If he is underweight, you’ll have to figure out why. That could mean his diet needs to be changed, his teeth need attention, his worm load is too high, or several other health reasons. Keeping track of weight changes and making small adjustments early is definitely better than waiting until there are big, obvious health problems. It’s also important to know your horse’s weight so you can give medications such as dewormer correctly. You don’t want to overdose or underdose him.

But how to weight him? Unfortunately, you can’t just ask your horse to step on the bathroom scale. The good news is that there is an easy measurement you can do at home to get a pretty darn accurate weight for your horse. You may have seen my docs and techs do this when they come out to give your horse his vaccines. You can do it just as easily yourself! It doesn’t require any special equipment, just a flexible tape measure and a calculator (unless you really like long division). A metal tape measure isn’t bendy enough, but a fabric or plastic one with inch markings works great.

Here’s what you do:

1. Stand your horse on a relatively flat surface. He should be standing “square”, with his legs placed evenly, not stretching one forward or back too much.
2. Measure around your horse’s heart girth: Holding the “zero” end of the tape, place the other end of the tape over his back behind his withers (about where his mane ends). Reach under his belly and pull the end of the tape under his barrel about where the girth would sit. Bring the tape up to meet the end with the “zero”. The number on the weight tape where the “zero” meets is the heart girth number.
3. Measure his length: Place the “zero” end of the tape at the center of his chest. Measure the length of his body straight back along his side to the crease between his muscles just below the point of his buttock.
4. Plug your 2 measurements into this formula. Choose the right one based on whether he is an adult, a yearling, or a weanling.

 Adult horse weight in pounds = heart girth x heart girth x length, and divide that number by 330.

Yearling horse weight in pounds = heart girth x heart girth x length, and divide that number by 301.

Weanling horse weight in pounds = heart girth x heart girth x length, and divide that number by 280.

To make it easier for you to see this in action, I had Dr. Yorke make a video on how to do the measurements. As the official Springhill Equine supervisor of all things, I made sure it was correct. You’re welcome.

If you weigh your horse every month and keep a chart, you’ll notice anything out of the ordinary. If that happens, you can give my docs a call to help you figure out what’s going on and find the appropriate solution.

Until next week,

~Tony

P.S. While you’re on my YouTube channel, take a minute and look around! There is a ton of great information there. Lots of ‘how-to’ videos in addition to some really good seminars. See, I give you all of these resources, and all I ask in return is for a treat and a scratch around my ears. It’s a pretty good deal if you ask me.